Rock, Paper, Scissors, Lizard, Spock

Rock, Paper, Scissors, Lizard, Spock is a variation on the game Rock, Paper, Scissors.
The rules of the game are very simple:

"Scissors cuts paper, paper covers rock,
rock crushes lizard, lizard poisons Spock,
Spock smashes scissors, scissors decapitates lizard,
lizard eats paper, paper disproves Spock,
Spock vaporizes rock, and as it always has, rock crushes scissors."
-Sheldon Cooper, The Big Bang Theory

If that does not seem very simple, there is a handy chart provided above.

Credits:
Win conditions image is an edited version of Pierre ciseaux feuille lézard spock.svg created by Nojhan, edited by DMacks. Licensed under GFDL/ CC-BY-SA-3.0, 2.5, 2.0, 1.0.
Poetsen One font created by Rodrigo Fuenzalida, Pablo Impallari. Sourced from Google Fonts, licensed under Open Font License.